Bizarre British Travel Habits

Many years ago, when the British upper crust traveled to what was then the colony of India, they went by ship. (British Airways hadn't been invented yet.) If they were sufficiently wealthy, they would ask for a stateroom on the port, or left, side of the vessel on the way to India.

On the trip home to Merrie Olde England, they would ask for accommodations on the starboard, or right, side. Out of this peculiar custom, a word was invented. What was that word?